Ebola virus and Marburg virus make up the family Filoviridae. The family is divided into two genera, currently designated as “Ebola-like viruses” and “Marburg-like viruses.” There are four subtypes within the “Ebola-like viruses,” Zaire (type species), Sudan, Reston, and Côte d'Ivoire (Ivory Coast). A single type, Marburg virus, makes up the “Marburg-like viruses.”
The glycoprotein (GP) is the sole structural protein making up the virion surface spikes that mediate virus entry into susceptible host cells through receptor binding. GP is the most studied of the filovirus proteins, not only for its importance in virus entry and pathogenesis but because it is a prime target for vaccine development. Research on filovirus GP has been facilitated through the use of recombinant DNA technology to permit biochemical and functional assays without the constraints of working with the infectious filovirus.
GP expression in cultured human endothelial and epithelial cells causes cell rounding and detachment (Yang Z.-Y. et al. 2000 Nat Med 6:886-889). These effects require the presence of the mucin-like serine and threonine-rich domain of GP. The cytotoxic effects of GP on macrophage and endothelial cell function disrupt inflammatory cell function and the integrity of the vasculature. In addition, by altering the cell surface expression of adhesion proteins and immune recognition molecules, Ebola virus may disrupt processes critical to immune activation and cytolytic-T-cell function. These phenomena likely account for the dysregulation of the inflammatory response and the vascular dysfunction characteristic of lethal Ebola virus infection, providing a rationale for focusing on GP as a target for a preventative vaccine.